fix(html): reduce inline images to alt text under markdownify 1.x (convert_as_inline → parent_tags)

[lntutor]

What's broken

markdownify ≥1.0 changed the convert_* calling convention: it now invokes them as convert_fn(node, text, parent_tags=<set>) (where parent_tags contains the pseudo-tag "_inline" for headings/table cells) instead of the old positional convert_as_inline boolean. _CustomMarkdownify.convert_img still declares convert_as_inline and swallows parent_tags into **kwargs, so convert_as_inline is always False and the alt-text reduction never fires:

HtmlConverter().convert_string('<h1>Hello <img src="a.png" alt="World"></h1>').markdown
# '# Hello ![World](a.png)'   -- expected '# Hello World'

An image in a table cell yields | ![AA](a.png) | bob |, which with a long/data: URI can break the table row entirely. Base markdownify.convert_img handles this correctly via "_inline" in parent_tags; the override defeated it.

Fix

Switch the override to accept parent_tags and check "_inline" in parent_tags, matching base markdownify. Block (paragraph) images and the data: URI truncation path are unaffected.

Tests

Adds three cases to test_module_misc.py: inline image in a heading and in a table cell reduce to alt text; a block image is still rendered. All pass. (convert_hn/convert_a/convert_input carry the same obsolete signature but produce no visible wrong result, so this stays a minimal single-bug fix.)

[lntutor]

@microsoft-github-policy-service agree [company="Vexere"]

[lntutor]

@microsoft-github-policy-service agree
@microsoft-github-policy-service agree company="Vexere"